Elongin-B (ELOB)

SIII, also referred to as elongin, is a general transcription elongation factor that increases the RNA polymerase II transcription elongation past template-encoded arresting sites. Subunit A is transcriptionally active and its transcription activity is strongly enhanced by binding to the dimeric complex of the SIII regulatory subunits B and C (elongin BC complex) (PubMed:7638163).

In embryonic stem cells, the elongin BC complex is recruited by EPOP to Polycomb group (PcG) target genes in order create genomic region that display both active and repressive chromatin properties, an important feature of pluripotent stem cells (By similarity). .